Kansetsu waza

“Kansetsu waza” (Joint locks) consist of using one’s own legs, arms, and knees, etc., to grasp the opponent’s joint (elbow, knee, etc.), and bend it in the reverse direction to lock the joint, thereby rendering him virtually helpless.
Kansetsu waza (Joint locks) belong to the “Osae komi waza” (Hold-down techniques), “Shime waza” (Strangling techniques), “Katame-waza” (Grappling techniques) 
Most of the Kansetsu waza (Joint locks) use the “lever principle” to lock the opponent’s joint. Because Kansetsu waza (Joint locks) pose considerable risk of injury, they are prohibited in the junior division.

The Kodokan and IJF Academy teaching videos are 60 seconds in length.